IQIM Postdoctoral and Graduate Student Seminar

Fermi Arcs and Their Topological Character in the Candidate Type-II Weyl Semimetals WTe2 and MoTe2

Flavio Yair Bruno, Ambizione Research Fellow, University of Geneva

Abstract: Recent theoretical work predicts that WTe2 and MoTe2 are examples of type - II Weyl semimetals, a new phase of matter hosting Weyl fermions as low energy excitations. The type – II Weyl points are connected by arc-shaped features, known as Fermi arcs, which can be observed with angle-resolved photoemission spectroscopy (ARPES). In this talk I will present a unifying picture of the surface and bulk electronic structure of WTe2 and MoTe2. This is achieved by combining laser and synchrotron based ARPES measurements with surface band structure calculations. In both materials we observe arc-like surface states "Fermi-arcs". I will discuss the robustness of the identified Weyl semimetal state and the topological character of the Fermi arcs based on systematic electronic structure calculations simulating different Weyl point arrangements.